Gaskets are often used as seal between mating metal surfaces. One common application involves the placement of a gasket between a head and an exhaust manifold of an internal combustion engine. Another application involves gasket placement between the exhaust manifold and an exhaust pipe flange. Gaskets for either application can be considered high temperature gaskets and more particularly exhaust manifold gaskets since they provide an exhaust seal which prevents the byproducts of combustion exiting the engine from escaping into the engine compartment of a vehicle.
Exhaust manifold gaskets are typically installed by placing the gasket between an exhaust manifold and its mating component and aligning bolt holes or apertures formed in the gasket with corresponding holes formed in the manifold and mating component. Typically, a threaded fastener passes through the manifold and gasket and engages a corresponding threaded aperture formed in the mating component. Some maneuvering of the manifold and gasket relative to the mating component may be required to align the holes therein with the corresponding threaded apertures of the mating component before the fasteners can be inserted. However, during the assembly process, the gasket may slip from its desired position or drop off the end of the inserted fastener before it can be fixed in place between the exhaust manifold and its mating component.
Attempts have been made to retain a gasket against a mating component prior to and during assembly by providing separate clips for attaching the gasket to a gasket attaching portion of an engine part. Using such clips, a gasket is placed adjacent the mating component, and the separate clip is attached to the mating component such that the gasket is secured in place between the clip and the mating component. The separate clips typically include one end for contacting the gasket about an outer periphery thereof while a second end is attached to an outer periphery of a mating component or to an outer periphery of a connecting portion between mating components. Use of such separate clips does not eliminate the problems involved in the assembly process whereby a gasket may slip from its desired position. The clip attached to an outer periphery of the mating component may be jostled or become otherwise dislodged by contacting adjacent parts. Further, separate clips may become dislodged during sub-assembly handling and shipping of mating components, allowing the gasket to slip or drop. As a result, the gasket sealing portion may become offset or mis-aligned from the holes to be sealed before assembly, again requiring some maneuvering of the manifold and gasket relative to the mating component during assembly in order to achieve a tight seal. Assembly of a gasket to a mating flange using separate clips is also a complex operation, requiring multiple parts and means to hold the gasket adjacent the mating flange while the clips are attached. Finally, because such clips are designed to interact with an outer periphery of a gasket, the gasket itself must cover the full radial extent of a mating surface.